Duke Ellington was an early band leader who was also a prolific composer. He was a leader of a jazz orchestra back in the early 20th century until his death in 1974. Apart from being a pianist and leader of this band, he was also a composer who prided himself on many popular compositions he wrote for the band and some other projects.
Practice. Sketch random things, learn how to do stuff.
Be patent. It'll take a while to actually learn how to.
